Vacuum pumping apparatus



Sept- 16; 1947- P. F. BEssY vAcnnl PUuPIuG APPARATUS Filed Oct. 18. 1944nventor Peter essg Patented Sept. 16; 1947'- UNITED STATES PATENT OFFICEVACUUM PUMPING APPARATUS Peter F. Bessy, Detroit, Mich.Application'October 18, 1944, Serial No. 559,180 I (o1. 23o-2) 3 Claims.

This invention relates to vacuum pumping ap' paratus and particularly tothe production of a vacuum for energizing a windshield wiper or otherautomotive appliance. y

In the practice now common, vacuum motors such as are used on motor-vehicles to actuate windshield Wipers and other appliances' deriveenergy from the vehicle engine through provision of a suction lineleading to the engine intake.`v

Such arrangements are open to serious objection for the reason that theapplied vacuum effect has a wide range of fluctuation and falls olimaterially asengine load increases and in many installations, failscompletely to energize themotor, when conditions are especiallyadverse.y Such arrangements, therefore, 'are least dependable underconditions rendering their satisfactory performance most vital.

It has been proposed to eliminate reliance aforementioned on vacuuminduced in the engine cylinders by deriving a vacuum from a gear type ofpump driven by the engine, crank case oil being circulated through suchpump for sealing purlposes. This is believed an unsatisfactory solutionof the problem because crankcase oil is an engine lubricant and as suchis too thin to `properly seal an inexpensive rotary pump. Moreover, theinitial thinness of said oil is materially increased through engineheat. -Also suchoil frequently is badly fouled by carbon from thecylinders.

An object of the invention is to provide an apparatus that will applydependable energy to a vacuum motor under substantially all conditionsof engine operation.

Another object is to utilize an inexpensive type of bladed, rotary pumpfor evacuating the suction line of a vacuum motor, and to maintain thenecessary seal at the blades-of such motor by circulating a suitablequantityof oil through the pump chamber.

A further object is to adapt my improved pumping., apparatus to beinstalled and operated independently of the lubrication system of thevehicle engine, so that it may use a sealing oil of viscosity bestsuited to the desired seal rather than to engine lubrication.

A further object is to provide for the actuation of a vacuum motoreither by) a small pump or by vacuum induced,l in the engine cylinders,Whichever is at 'a given time more powerful.

A further object is to safeguard theA apparatus vacuum motor.

t.against any access of the circulating oil to the These and variousother objects are attained 5 2 by lthe construction hereinafterdescribed and illustrated in the accompanying drawing, wherein:

Fig. 1 is a diagrammatic viewv of the apparatus prising a disk 4 smallerthan said chamber and occupying a substantially tangential relation toits periphery, and a plurality of blades 5 slidingly fitted in slots ofsaid disk and projecting beyond the disk periphery to engage that of thechamber 2. The disk and blades are of an equal width such as to maintainsealing contact With the side walls of said chamber. Said disk iscentrally secured on and driven by a shaft 6, suitably journaled in saidcasing, and centrifugal force urges the blades outwardly and against theperiphery of the chamber 2 when the disk is driven,

the blades sliding in or out according as they approach or recede fromthe pointof tangency. It is preferred to journal the shaft in ballbearings mounted in the casing at opposite sides of the impeller, onesuch bearing 'I being set into an embossed central portion of the cover3 and the other, 8 occupying a` housing formed by an annular ange 9 onthe casing I. An oil seal I0 of ordinary construction is press tted insaid housing in exterior contact with the bearing 8. The described pumpmay be supported and driven in any desired manner and,A as illustrated,is bolted to a. bracket II serving to attach it to the engine l2 of amotor vehicle (not shown), being driven by a pulley I3 rotated by thefan driving belt I4.

An inexpensive pump of the described character would be quiteunsatisfactory for vacuum purposes in absence of some provision foradequately sealing the sliding intersections of the blades with the pumpcasing, and it has been found that a quite satisfactory seal is obtainedby continuously flowing through the pump a small quantity of a fairlyheavy oil. It has been further found that such oil may be convenientlydelivered to and discharged from the pump together with the impelledair. Thus an oil reservoir I5 is exteriorly mounted on the engine I2 andhas 3 a restricted outlet IB discharging from its bottoml manifold andoil connection I6 is a pipe I9 ex- 4 n `since, the oil circulationinvolves only a trliiing diminution.

tending to an ordinary vacuum motor 20 actuatlng any desired appliance-as for example the illustrated Windshield wiper 2|. Thus thepump takeseffect on the vacuum motor jointly through the pipes I1 and I9. It ispreferred Vto insert a check valve 22 in the pipe I1 between itsconnections I6 and I9, such valve allowing a free ilow toward thepumpbut positively preventing reverse iiow. Such valve has two essentialfunctions,- namely, the prevention of oil delivery either to .the vacuummotor or to the intake manifold. In absence of the check valve, shuttingoi of the engine would produce an oil flow to the motor to satisfy thevacuum left in such motor. In the' next subsequent use of the wiperthere would be an exhaust of such oil from the motor, whereby thewindshield would be badly smeared. Also in absence of said check valve,there would be a ilow of oil into the intake manifold Whenever enginesuction exceeds that of the pump, with result that the reservoir I wouldsoon be emptied ardized.

il.. f

, It is to be noted nally that my system is. quite easily installed andentails no objectionable perforation of the engine crank-case, nor anydisturbance oi lubrication systems -as now stand- What I claim is: 1. Ina vacuum motor drive system, the combination with a vacuum-inducingpower-plant and a vacuum-inducing rotary pump, of intercommunicatingsuction connections .'irom the power plantand the inlet oi.' said pumpto an area to be evacuated, means for maintaining a -a vacuum-inducingrotary pump, of a connection and the wiper would be inopera 've or onlypartially operative during such oil fl w.

Air and oil discharging from the pump I are conducted-by a pipe 23 tothe upper portion of the reservoir I5, the air being Vented from theupper portion of the reservoir through an outlet 24.

In operation of the described system of energizing a vacuum motor, alloperatingl conditions are fully met, the motor being responsive toeither the pump I or engine manifold, whichever is pro- ,ductive ofhigher. vacuum. When the engine vacuum drops oi due to a heavy load orto engine acceleration, the pump will prevent any corresponding decreasein efciency of the motor. When the engine is idling at a speedinadequate to get the best results from the pump, the engine will beproducing a high vacuum and will assure eflicient operation of themotor.

As compared to a system attempting to use engine oil for establishing apump seal, the construction described has Vital advantages. When a heavyoil is best suited to sealing purposes but poorly suited to enginelubrication, it is clear thatpoor results must follow from Aan eiort tomake one oil serve both purposes. The present between the inlet of saidpump, the low pressure area of said power plant, and an area to beevacuated whereby evacuation may be eiected by either the power plant orpump, means for delivering oil to said connection for sealing the pump,and a check valve resisting oil ow through said connection to either thepower plant low pressure area or the, area to be evacuated.

`3. In a vacuum motor drive system, the combination with avacuum-inducing power plant and a vacuum-inducing rotary pump, of an oilreservoir exteriorly mounted upon said power plant and vented to theatmosphere above the normal oil level, of intercommunicating suctionconnections from the power plant and the inlet of "the pump to an areato be evacuated, a restricted oil delivery connection from saidreservoir to said suction connection opening into said reservoir fromthe pump-outlet, and means resisting oil ow in said connections to thepower plant and area to be evacuated.

PE'IER, F. BESSY.

REFERENCES CITED The following references are of record in the le ofthis patent:

Hueber et al Feb. 25, 1936

